[BVARC] Lightning

[Westley Clavey]

After all this discussion, I went on a field trip around the house, 
garage and attic to note the grounding points.

There is no intersystem grounding block, per se.� There is a #6 ground 
wire from the AC Service breaker box to a ground rod located at the back 
of the garage.� When AT&T installed our cable, they ran a second #6 wire 
to a clamp they added to the same ground rod. So they are, in effect, 
grounded to the same point.

There is a clamp on an exterior cold water pipe near the kitchen, but I 
cannot figure out where that wire goes.� This is a very heavy stranded 
copper cable in this clamp, probably 3/8" in diameter.

The service ground is on the back of the garage.� My shack is on the 
diagonal corner of the property, probably 150-160' away in a straight 
line across the yard, the patio, and around the garage.� I have no idea 
what the right way to connect them would be... if I wanted to run a wire 
from my station ground to the service ground, It would probably be close 
to 200' long, taking into account the things I need to go around.� Is 
that a low impedance connection?

I was hoping that I could locate that very heavy line up in the attic 
somewhere with all our utility equipment.� Hoping that it, too, is 
connected to the service ground, it would be easier to connect my 
station ground to that, but no luck.� I don't know how to proceed.

On 5/27/21 2:25 PM, Robert Polinski via BVARC wrote:
>
> Most lightning damage done in a house is due to a poor grounding 
> system on the AC service. All service panels should have at least 1 
> 8ft ground rod with a min of #6 ground wire going to the panel board. 
> The size of this conductor is dependent on the size of the service. In 
> many cases, this ground is missing, the clamp has rusted off, or is 
> just making a poor connection. In many areas, the copper thieves have 
> cut the pole grounds, making your rod the last defense before the 
> surge hits your home. Ground rods need to have an impedance of lest 
> than 25 ohms, sometimes more than 1 rod is needed to get this. 
> Warning, before you do any checking or service on your grounding 
> system, turn off your main breaker & test your ground wire with a 
> clamp on amp meter. If it indicates any current, it is a sign that the 
> power co. ground is bad & working on it could cause electrocution. 
> Call an electrician.
>
> ����The second issue is the failure to bond all grounds together. 
> Newer electrical services are required by code to have a intersystem 
> bonding block. On this block it has terminals for bonding CATV phone & 
> any other systems to the service ground. You ham station grounding 
> system MUST be bonded (connected) to this system with a #6 ground 
> wire. This is a NEC code requirement and a must to prevent station 
> damage �& possibly a fire. If you do not connect the 2 systems 
> together, and a strike hits the power line, the lightning will seek 
> the lowest impedance �path to ground. If your station ground is lower 
> than the service ground, it will pass thru your equipment to find it. 
> Bonding the ground together eliminates this problem. Robert KD5YVQ
>
>
> ________________________________________________
> Brazos Valley Amateur Radio Club
>
> BVARC mailing list
> BVARC at bvarc.org
> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
> Publicly available archives are available here: https://www.mail-archive.com/bvarc@bvarc.org/

-- 
Wes Clavey, W5WMC

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.bvarc.org/pipermail/bvarc_bvarc.org/attachments/20210527/b44199f8/attachment.htm>